1. Field of the Invention
This invention relates to a continuous electric power supply device that absorbs slack of a wire harness on opening and closing a slide structure by loading the wire harness with an elastic member in a protector.
2. Description of the Related Art
FIG. 19–20 show one embodiment of a continuous electric power supply device by prior art (see Patent reference 1).
The continuous electric power supply device 60 applied for a slide door 61 of a vehicle includes a synthetic resin protector 62 and a metallic flat spring 64 disposed to rise from bottom to top in the protector 62. The continuous electric power supply device 60 prevents slack of a wire harness 63 by loading the wire harness 63 upwardly with the flat spring 64. The protector is provided with a base and a cover that is omitted in the figures.
One end of the wire harness 63 is led from the protector 62 into the slide door 61 to be connected with an electric device or an auxiliary device, such as a motor for a power regulated window, a door lock unit and an automatic opening/closing door unit. The other end of the wire harness 63 is led through a traversing space 66 to a vehicle body 67 and connected with a power supply.
In the completely closed slide door 61 of FIG. 19, the wire harness 63 is pulled backwardly against the spring load. In the near full opened slide door 61 of FIG. 20, the wire harness 63 is pulled forwardly against the spring load. Though the wire harness 63 intends to be slacked largely in the partially opened slide door 61, the wire harness 63 is received in curved form into the protector 62 by a restoring force of the flat spring 64. Thereby, clamping the slack of the wire harness between the traversing space 66 is prevented.
FIG. 21 shows the other embodiment of a continuous electric power supply device by prior art (see Patent reference 2).
The continuous electric power supply device 70 applied for a slide door of a vehicle includes a synthetic resin protector 71 and a flat wire harness 72 being received to be formed into an S-shape in the protector 71. And respective curved portions of the wire harness 72 are supported slidably by a pair of rollers 73, 74.
One roller 73 is pivoted by the protector 71, and the other roller 74 is movable along an oval guide hole 75 of the protector 71. When the protector 71 is disposed in the slide door, the other roller 74 supported by a pin 76 of the vehicle body moves in an opening/closing direction of slide door, so that the wire harness 72 is led from an opening 77 of the protector 71.
References are following:
Reference 1: Japan Patent Application Laid open 2001-354085, page 7–9, FIG. 4–7; and
Reference 2: Japan Patent Application Laid open 2001-128348.
Objects to be Solved
However, the aforesaid continuous electric power supply device of FIG. 19 may be increased in height for receiving the wire harness 63 in a half circle shape in the protector 62. Therefore, a large room for receiving may be required in the slide door 61.
The aforesaid continuous electric power supply device of FIG. 21 forms the wire harness 72 with a small radius along the two rollers 73, 74. Thereby, when using a usual round wire harness instead of the flat wire harness 72, sliding friction between the roller 74 and a wire harness is increased, so that absorbing slack of the wire harness cannot be done smoothly. A large bending stress is loaded on the wire harness, so that the wire harness would have time-dependent wear and damage.
To overcome the above drawback, an object of this invention is to provide a continuous electric power supply device that can miniaturize a device structure such as a protector, and absorb slack of a wire harness smoothly, and increase bending durability of the wire harness.
How to Attain the Object
In order to attain the object, a continuous electric power supply device according to the present invention includes a wire harness being formed into a loop shape and an elastic member being disposed along a loop portion of the wire harness. The elastic member energizes the loop portion in an expansive radial direction.
According to the power supply device mentioned above, when the wire harness is pulled in accordance with open/close of the slide structure, the elastic member is shrunk in the radial direction integrally together with the loop portion of the wire harness and loads elastically the loop portion to be expanded in the radial direction. When the slide structure is partially opened, the wire harness intends to be slacked much, but the loop portion is expanded in the radial direction by a restoring force of the elastic member and the slack is absorbed.
The elastic member is always touching or contacting with the loop portion partially or throughout the length. Thus, the elastic member supports the loop portion by the whole length, so that the loop portion is maintained always in round or near round shape. Thereby, the wire harness does not have a partial stress, and the slack can be absorbed smoothly, and the bending durability of the wire harness is improved. The wire harness is formed in a loop shape, so that the power supply device is miniaturized in comparison with usual curved forming.
The continuous electric power supply device is further specified in the above device by that the loop portion and the elastic member are disposed in a protector.
According to the device mentioned above, the loop portion of the wire harness is protected from interference with outside by the protector. The loop portion can be expanded effectively in a space of the protector, so that the protector can be miniaturized.
The continuous electric power supply device is further specified in the above device by that the protector includes an opening for leading out the wire harness and a guide portion for supporting the loop portion disposed at an opposite side of the opening.
According to the device mentioned above, the wire harness is led from the opening of the protector, and the loop portion of the wire harness is shrunk together with the elastic member in the radial direction at a support point of the guide portion. When the loop portion is expanded in the radial direction, the loop portion is supported at the guide portion without slack. The guide portion ensures to maintain the loop portion in round shape and assures the minimum curved radius to control bending form.
The continuous electric power supply device is further specified in the above device by that the protector is provided with a guide wall separating the loop portion and a harness portion continued to the loop portion.
According to the device mentioned above, the guide wall separates the loop portion and a portion at lead-out side of the wire harness. Thereby, when pulling the wire harness out and drawing the wire harness in, wear between the loop portion and the portion at lead-out side, and wear between the elastic member at the loop portion and the portion at lead-out side are prevented.
The continuous electric power supply device is further specified in the above device by that the elastic member is a flat spring, and the flat spring is disposed along an inner surface of the loop portion.
According to the device mentioned above, the flat spring is disposed with a curved or loop shape along the inner surface of the loop portion and loads the loop portion to be expanded in the radial direction. A bottom end of the flat spring is fixed and a top end of the flat spring is a free end. The bottom end of the flat spring is preferably positioned at an opposite side against the oval opening of the protector. The flat spring is always touching or contacting with the inner surface of the loop portion without sliding.
The continuous electric power supply device is further specified in the above device by that the flat spring has such a length to form a loop shape with an intersection.
According to the device mentioned above, the loop portion of the wire harness is statically supported throughout with a uniform force by the loop-shape flat spring. Thereby, the loop portion is maintained in round or near round shape, so that the wire harness does not have a partial load and the slack thereof is absorbed more smoothly and the bending durability is more improved.
The continuous electric power supply device is further specified in the above device by that the elastic member is a coil spring and the loop portion is inserted through an inside of the coil spring.
According to the device mentioned above, in accordance with an action of leading out the wire harness, the loop portion of the wire harness is shrunk in the radial direction and the coil spring is compressed in lengthwise thereof at support point of a fixed bottom end. The top end of the coil spring moves toward the bottom end in a compressing direction, and an inner surface of the coil spring slides on an outer surface of the loop portion. The compressed coil spring has a restoring force in a direction of expanding the coil spring. When the wire harness intends to have large slack in the partially opened slide structure, the slack is absorbed by expanding the loop portion in the radial direction by the restoring force. The coil spring expands in a top end direction at the support portion of the bottom end. A spring constant of the coil spring is substantially constant, so that the restoring force may not increase or decrease rapidly and the loop portion is smoothly expanded in the radial direction.
The continuous electric power supply device is further specified in the above device by that a bottom end of the coil spring is fixed, at a fixed side of the loop portion, on the loop portion or the protector, and a top end of the coil spring is fixed on the protector at a moving side of the loop portion to be slidable against the loop portion.
According to the device mentioned above, in accordance with an action of leading out the wire harness, the loop portion of the wire harness is shrunk in the radial direction and the coil spring is compressed in lengthwise thereof at support point of a fixed bottom end. The top end of the coil spring moves toward the bottom end in a compressing direction, and an inner surface of the coil spring slides on an outer surface of the loop portion. The compressed coil spring has a restoring force in a direction of expanding the coil spring. When the wire harness intends to have large slack in the partially opened slide structure, the slack is absorbed by expanding the loop portion in the radial direction by the restoring force. The coil spring expands in a top end direction at the support poring of the bottom end. A spring constant of the coil spring is substantially constant, so that the restoring force may not increase or decrease rapidly and the loop portion is smoothly expanded in the radial direction.
The continuous electric power supply device is further specified in the above device by that the coil spring is provided at the top end thereof with a cylindrical harness guide.
According to the device mentioned above, when the top end of the coil spring slides along the loop portion of the wire harness, sliding motion between the wire harness is acted smoothly without sticking by the harness guide.
The continuous electric power supply device is further specified in the above device by that the coil spring is formed to have a smaller diameter toward the topside thereof for contacting the loop portion so as to bend the loop portion with a large radius.
According to the device mentioned above, a small radius portion at the top end of the coil spring contacts slidably with the loop portion of the wire harness with little gap in a suitable length. Suitable strong bending stiffness of the small radius portion controls a radius of the bent wire harness and folding the wire harness at the top end of the spring is eliminated.
The continuous electric power supply device is further specified in the above device by that the elastic member is a spiral spring disposed inside the loop portion.
According to the device mentioned above, when opening or closing the slide structure, the loop portion of the wire harness is shrunk in the radial direction together with the spiral spring in accordance with an action of leading out the wire harness, and loaded to be expanded in the radial direction by the spiral spring. When the slide structure is in a partial opened condition, the wire harness intends to have large slack, but the slack is absorbed by expanding the loop portion by an elastic reaction force of the spiral spring. An outermost surface of the spiral spring contacts with the inner surface of the loop portion. The spiral spring is shrunk uniformly in the radial direction at a support point of the center thereof to provide uniform load force against the loop portion.
The continuous electric power supply device is further specified in the above device by that the spiral spring is turned from a center area of the loop portion to a direction to lead out the wire harness.
According to the device mentioned above, in accordance with an action of shrinking the loop portion of the wire harness in the radial direction, the top end of the spiral spring is pulled integrally toward a direction of pulling out the wire harness. Thereby, the spiral spring is shrunk smoothly. If the spiral spring is turned in an opposite direction, when the wire harness is pulled out, the top end of the spiral spring is pulled to expand the spiral spring. Therefore, the spiral spring cannot be shrunk smoothly.
The continuous electric power supply device is further specified in the above device by that a center side end of the spiral spring is fixed on the protector, and a top end of the spiral spring is fixed on the loop portion.
According to the device mentioned above, the spiral spring and the loop portion of the wire harness are integrally shrunk and expanded in the radial direction without a slip therebetween.
The continuous electric power supply device is further specified in the above device by that the center side end of the spiral spring is formed into an asymmetric convexo-concave shape for preventing from assembling the spiral spring oppositely on the protector.
According to the device mentioned above, even if trying to mount the spiral spring oppositely on the protector, a convex portion of the spiral spring is not fitted into a concave portion of the protector. Thereby, the spiral spring can not be mounted and prevented from an error of mounting.
The continuous electric power supply device is further specified in the above device by that the top end of the spiral spring is fixed through a fixing member on the loop portion.
According to the device mentioned above, the top end of the spiral spring and the loop portion of the wire harness are fixed easily and securely with the fixing member. The fixing member may include a spring inserting opening and be fixed on the loop portion by integral molding.
The continuous electric power supply device is further specified in the above device by that a protecting tube at the loop portion and a protection tube at lead-out side of the wire harness are connected together through a connecting member.
According to the device mentioned above, two types of protecting tubes with different materials and different shape can be connected together easily and securely with the connecting member, and the wire harness is structured. The connecting member may be fixed on one protecting tube by insert-molding so as to have a holding portion for the other protecting tube.